Cambridge 20 Test 4 Reading Answers & Explanations

This post provides complete answers and clear explanations for Cambridge IELTS 20 Academic Reading Test 4.

Each answer includes:

• Strategy
• Keywords
• Exact paragraph and line location
• Explanation
• Correct answer

> Location note: The paragraph and line locations below refer to the supplied Cambridge 20 Reading Test 4 material.

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How This Guide Is Structured

Strategy

The strategy explains the best method for solving each IELTS Reading question type.

Keywords

Keywords are the important words and phrases that help you locate the relevant information quickly.

Exact Paragraph and Line Location

Each answer identifies the relevant passage, paragraph or section, and line range.

Explanation

The explanation shows how the question matches, paraphrases or contradicts information in the passage.

Correct Answer

The final answer appears after the explanation.

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Reading Passage 1

Georgia O’Keeffe

Questions 1–7: Note Completion

Strategy

For note-completion questions:

1. Read all the notes before scanning.
2. Identify dates, places and major stages of the person’s life.
3. Predict whether the blank requires a person, material, object or place.
4. Follow the passage chronologically.
5. Look for paraphrases.
6. Copy only the required word from the passage.

The instruction says:

Choose ONE WORD ONLY from the passage for each answer.

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Question 1

O’Keeffe studied art and later worked as a ______ in different parts of the USA.

Keywords

studied art, worked, various places, USA

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 2, lines 10–16

Explanation

After studying art and completing further education, O’Keeffe became an art teacher.

She taught in schools and colleges in Virginia, Texas and South Carolina.

So, the answer is: teacher

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Question 2

She produced drawings using ______ which were later exhibited in New York.

Keywords

drawings, exhibited, New York, material

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 3, lines 17–22

Explanation

O’Keeffe experimented with abstract compositions made in charcoal.

Some of these drawings were later shown to Alfred Stieglitz and exhibited at his New York gallery.

So, the answer is: charcoal

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Question 3

She became famous for paintings of New York’s ______.

Keywords

New York, famous paintings, architectural pictures

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 5, lines 28–30

Explanation

By the mid-1920s, O’Keeffe was widely recognised for architectural paintings showing New York’s tall buildings.

The passage specifically identifies them as skyscrapers.

So, the answer is: skyscrapers

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Question 4

She produced innovative close-up paintings of ______.

Keywords

close-up, innovative, magnified images

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 5, lines 30–38

Explanation

O’Keeffe created magnified images of flowers.

She enlarged tiny details so that the shapes filled large canvases and appeared almost abstract.

So, the answer is: flowers

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Question 5

In New Mexico, she was initially inspired by the many ______ she found there.

Keywords

New Mexico, initially inspired, found

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 7, lines 44–49

Explanation

When O’Keeffe first began working in New Mexico, she became fascinated by sun-bleached bones scattered across the landscape.

These inspired several important paintings.

So, the answer is: bones

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Question 6

For more than forty years, she painted features forming New Mexico’s dramatic ______.

Keywords

forty years, New Mexico, dramatic features

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 8, lines 50–53

Explanation

The passage says New Mexico’s unusual geological formations, vivid colours, light and vegetation formed a spectacular landscape that inspired O’Keeffe for more than four decades.

So, the answer is: landscape

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Question 7

During later air travel, she painted clouds and ______ seen from above.

Keywords

plane, later years, clouds, aerial views

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 10, lines 60–64

Explanation

Flying inspired two of O’Keeffe’s final major series.

One contained aerial views of rivers, while another showed the sky and clouds from above.

So, the answer is: rivers

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Questions 8–13: TRUE, FALSE, NOT GIVEN

Strategy

For this question type:

• TRUE = the statement agrees with the passage.
• FALSE = the passage gives opposite information.
• NOT GIVEN = the passage does not provide enough information.

Do not assume something is true simply because the topic is mentioned.

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Question 8

Georgia O’Keeffe’s artistic style was strongly influenced by changing art fashions.

Keywords

style, influenced, changing fashions, art trends

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 1, lines 5–9

Explanation

The passage says O’Keeffe remained independent from changing artistic trends and remained faithful to her own vision.

The statement says the opposite.

So, the answer is: FALSE

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Question 9

By the time O’Keeffe finished high school, she had already chosen her future career.

Keywords

high school, chosen career, artist

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 2, lines 10–13

Explanation

The passage says that by the time she graduated from high school in 1905, she had already decided to become an artist.

The statement agrees with the passage.

So, the answer is: TRUE

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Question 10

Alfred Stieglitz first discovered O’Keeffe’s work when she sent drawings directly to his New York gallery.

Keywords

Stieglitz, drawings, gallery, first discovered

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 3, lines 17–22

Explanation

O’Keeffe did not send the drawings directly to Stieglitz’s gallery.

She sent them to a friend in New York, and that friend showed them to Stieglitz.

The statement therefore contradicts the passage.

So, the answer is: FALSE

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Question 11

O’Keeffe was photographed by Stieglitz over many years.

Keywords

Stieglitz, photographs, many years

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 4, lines 23–27

Explanation

Stieglitz produced black-and-white portraits of O’Keeffe over a twenty-year period from 1917 to 1937.

This clearly supports the statement.

So, the answer is: TRUE

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Question 12

O’Keeffe’s paintings of the patio at her Abiquiú house were among her favourite works.

Keywords

Abiquiú, patio, favourite

Exact Paragraph and Line Location

Reading Passage 1, Paragraph 9, lines 54–59

Explanation

The passage says the patio and its black door were particularly inspirational and appeared in more than thirty paintings.

However, it never says these paintings were among O’Keeffe’s personal favourites.

So, the answer is: NOT GIVEN

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Question 13

O’Keeffe produced more work during the 1950s–1970s than at any other stage of her life.

Keywords

1950s, 1970s, more work, any other time

Exact Paragraph and Line Location

Closest related location: Reading Passage 1, Paragraphs 10–11, lines 60–73

Explanation

The passage describes O’Keeffe’s travels and major painting series during this period.

It later says the final two decades of her life were relatively unproductive.

However, it does not compare her total output in the 1950s–1970s with every other period of her career.

So, the answer is: NOT GIVEN

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Reading Passage 2

Adapting to the Effects of Climate Change

Questions 14–17: Matching Information

Strategy

For matching-information questions:

1. Read all four statements first.
2. Identify distinctive keywords.
3. Skim paragraphs A–F for their main topic.
4. Scan for the detailed evidence.
5. Match meaning, not repeated vocabulary.

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Question 14

How a type of plant naturally protects coastlines

Keywords

plant, natural protection, coastlines

Exact Paragraph and Line Location

Reading Passage 2, Paragraph C, lines 154–165

Explanation

The passage describes mangroves.

Their root systems:

• trap sediment;
• raise the seabed;
• reduce the power of waves and tidal currents.

This explains how the plants naturally protect coastal areas.

So, the answer is: C

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Question 15

A prediction of how long climate-change effects would continue even if emissions stopped

Keywords

prediction, emissions stopped, effects continue

Exact Paragraph and Line Location

Reading Passage 2, Paragraph A, lines 140–145

Explanation

Scientists predict that even if all carbon dioxide emissions stopped immediately, global warming would continue for about forty years because of gases already released.

So, the answer is: A

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Question 16

A solution described as particularly cost-effective

Keywords

cost-effective, cheaper, solution

Exact Paragraph and Line Location

Reading Passage 2, Paragraph D, lines 169–178

Explanation

Amphibious houses are described as much cheaper than permanently raising conventional houses.

The cost is about one-third of replacing a building’s foundations completely.

So, the answer is: D

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Question 17

Technology used to identify areas most in need of intervention

Keywords

technology, identify areas, intervention, mapping

Exact Paragraph and Line Location

Reading Passage 2, Paragraph F, lines 191–200

Explanation

The Cool Streets LA programme used a Geographic Information System mapping tool.

This identified streets with low tree-canopy coverage and helped planners decide where cooling work was most needed.

So, the answer is: F

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Questions 18–22: Sentence Completion

Strategy

For sentence-completion questions:

1. Read all sentences before scanning.
2. Predict the grammatical form of the missing word.
3. Locate the corresponding paragraph.
4. Copy the exact word.
5. Follow the one-word limit.

The instruction says:

Choose ONE WORD ONLY from the passage for each answer.

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Question 18

Miami Beach installed efficient ______ as part of its stormwater programme.

Keywords

Miami Beach, stormwater, installed, water

Exact Paragraph and Line Location

Reading Passage 2, Paragraph B, lines 146–153

Explanation

Along with raising roads, Miami Beach installed new pumps capable of removing up to 75,000 litres of water every minute.

So, the answer is: pumps

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Question 19

The first stage of the Indonesian mangrove project involved building ______.

Keywords

Indonesia, mangroves, first stage, construction

Exact Paragraph and Line Location

Reading Passage 2, Paragraph C, lines 154–165

Explanation

Wetlands International built semi-permeable dams using bamboo poles and brushwood.

These structures imitate mangrove roots and create conditions that allow mangroves to return naturally.

So, the answer is: dams

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Question 20

In the Mekong Delta, houses have been designed to ______ when floodwater rises.

Keywords

Mekong Delta, houses, floodwater, rise

Exact Paragraph and Line Location

Reading Passage 2, Paragraph D, lines 169–178

Explanation

Unlike ordinary homes built on stilts, the modified houses were designed so they could rise with floodwater.

They were built to float.

So, the answer is: float

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Question 21

In Bangladesh, various ______ suitable for salty soil have been introduced.

Keywords

Bangladesh, salty soil, suitable, farming

Exact Paragraph and Line Location

Reading Passage 2, Paragraph E, lines 179–190

Explanation

Farmers were encouraged to grow naturally salt-tolerant crops.

Examples include certain varieties of carrot, potato, cabbage and beetroot.

So, the answer is: crops

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Question 22

A project in Los Angeles has increased the number of ______ on city streets.

Keywords

Los Angeles, increased number, streets

Exact Paragraph and Line Location

Reading Passage 2, Paragraph F, lines 191–198

Explanation

The Cool Streets LA projects include planting trees as part of efforts to reduce urban temperatures.

So, the answer is: trees

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Questions 23–26: Matching People

Strategy

Match each statement with the person who actually expresses the view.

List of People

• A — Yanira Pineda
• B — Susanna Tol
• C — Elizabeth English
• D — Raisa Chowdhury
• E — Greg Spotts

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Question 23

Strategies must involve and benefit local communities.

Keywords

communities, residents, long-term success

Exact Paragraph and Line Location

Reading Passage 2, Paragraph C, lines 162–165

Explanation

Susanna Tol argues that successful long-term approaches should use natural processes while involving and benefiting communities and local decision-makers.

So, the answer is: B — Susanna Tol

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Question 24

Reducing urban heat is essential for survival in this location.

Keywords

heat, survival, life and death, city

Exact Paragraph and Line Location

Reading Passage 2, Paragraph F, lines 191–195

Explanation

Greg Spotts says urban cooling is literally a matter of life and death for the future of Los Angeles.

So, the answer is: E — Greg Spotts

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Question 25

More adaptation work will be required in coming decades because of rising water.

Keywords

future decades, more work, water

Exact Paragraph and Line Location

Reading Passage 2, Paragraph B, lines 151–153

Explanation

Yanira Pineda says that in 20, 30 and 40 years, Miami Beach will need to return and make further adjustments as environmental conditions continue changing.

So, the answer is: A — Yanira Pineda

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Question 26

The number of locations needing flood-adaptation technology has increased.

Keywords

more locations, adaptation, flooding, technology

Exact Paragraph and Line Location

Reading Passage 2, Paragraph D, lines 171–174

Explanation

Elizabeth English says amphibious-house technology is now becoming necessary in places that did not previously need it.

This shows that the number of locations requiring such intervention has grown.

So, the answer is: C — Elizabeth English

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Reading Passage 3

A New Role for Livestock Guard Dogs

Questions 27–31: Matching Information

Strategy

For matching-information questions:

1. Read Questions 27–31 first.
2. Identify the central idea in each statement.
3. Skim paragraphs A–G.
4. Locate the paragraph containing the exact idea.
5. Remember that one paragraph may answer more than one question.

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Question 27

An example of a predator being protected after livestock guard dogs were introduced

Keywords

predator protected, guard dogs, example

Exact Paragraph and Line Location

Reading Passage 3, Paragraph D, lines 288–300

Explanation

In Namibia, farmers often killed cheetahs because they blamed them for livestock losses.

After guard dogs were introduced, livestock losses fell sharply and farmers became less likely to kill predators.

So, the answer is: D

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Question 28

An optimistic prediction about future benefits of livestock guard dogs

Keywords

optimistic, future, positive developments

Exact Paragraph and Line Location

Reading Passage 3, Paragraph G, lines 319–325

Explanation

The writer says that if guard dogs are used successfully, they could have a bright future in helping humans and wildlife live together more peacefully.

So, the answer is: G

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Question 29

How guard dogs keep predators away from livestock

Keywords

methods, guard dogs, predators away

Exact Paragraph and Line Location

Reading Passage 3, Paragraph B, lines 271–278

Explanation

Guard dogs:

• stand between livestock and threats;
• bark loudly;
• chase predators when necessary.

Often, simply being present is enough to deter predators.

So, the answer is: B

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Question 30

Claims from different researchers that guard dogs successfully protect livestock

Keywords

researchers, effective, herds, successful

Exact Paragraph and Line Location

Reading Passage 3, Paragraph C, lines 279–287

Explanation

The paragraph gives evidence from both Silvia Ribeiro and researchers Linda van Bommel and Chris Johnson.

Their studies found large reductions in livestock attacks after farmers began using guard dogs.

So, the answer is: C

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Question 31

How livestock guard dogs learn the skills needed for their work

Keywords

training, skills, raised, livestock

Exact Paragraph and Line Location

Reading Passage 3, Paragraph B, lines 271–278

Explanation

Guard dogs are raised from an early age with the animals they will eventually protect.

The livestock effectively becomes the dog’s family.

This early upbringing is central to their training.

So, the answer is: B

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Questions 32–36: Matching People

Strategy

List of People

• A — Dan Macon
• B — Silvia Ribeiro
• C — Linda van Bommel
• D — Julie Young
• E — Bethany Smith

Read each statement carefully and match it to the person who directly expresses that view.

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Question 32

Guard dogs may save the lives of both farm animals and wild predators.

Keywords

save livestock, save predators, both

Exact Paragraph and Line Location

Reading Passage 3, Paragraph D, lines 297–300

Explanation

Julie Young says that when livestock are not killed, farmers have less reason to request permission to kill predators such as wolves.

Guard dogs can therefore indirectly protect both groups.

So, the answer is: D — Julie Young

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Question 33

Reports that farmers changed their behaviour may not be completely reliable.

Keywords

reports, farmers, behaviour, accurate

Exact Paragraph and Line Location

Reading Passage 3, Paragraph E, lines 301–304

Explanation

Bethany Smith warns that farmers’ self-reported claims that they stopped killing predators should be treated cautiously.

This means those claims may not be fully reliable.

So, the answer is: E — Bethany Smith

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Question 34

Problems may occur if guard dogs are not used widely enough.

Keywords

not widespread, negative consequences, neighbours

Exact Paragraph and Line Location

Reading Passage 3, Paragraph E, lines 304–308

Explanation

Silvia Ribeiro warns that if only a few farmers use guard dogs, predators may simply move to neighbouring unprotected farms.

Those farmers may then kill the predators.

So, the answer is: B — Silvia Ribeiro

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Question 35

Guard dogs are the most effective way to protect farm animals if they are properly managed.

Keywords

most effective, livestock, managed properly

Exact Paragraph and Line Location

Reading Passage 3, Paragraph C, lines 279–287

Explanation

Linda van Bommel says livestock guard dogs are the most efficient control method available when they are managed and used correctly.

So, the answer is: C — Linda van Bommel

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Question 36

Training a livestock guard dog requires a different approach from training a household guard dog.

Keywords

training, livestock dog, house guard dog

Exact Paragraph and Line Location

Reading Passage 3, Paragraph B, lines 275–278

Explanation

Dan Macon explains that livestock guard dogs must form their strongest attachment to livestock.

Too much human affection may instead turn a puppy into a good household or porch guard dog.

So, the answer is: A — Dan Macon

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Questions 37–40: Summary Completion

Strategy

For summary completion:

1. Read the full summary first.
2. Predict the type of word required.
3. Find the relevant paragraph.
4. Copy the exact word from the passage.
5. Follow the one-word limit.

The instruction says:

Choose ONE WORD ONLY from the passage for each answer.

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Question 37

In Namibia, deaths increased among other predators, especially ______.

Keywords

Namibia, predator deaths, increased

Exact Paragraph and Line Location

Reading Passage 3, Paragraph F, lines 309–315

Explanation

Although guard dogs helped protect cheetahs, researchers found that killings of another predator increased.

The species was jackals.

So, the answer is: jackals

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Question 38

Guard dogs may carry ______ that affect wild animals.

Keywords

dogs, affect wild animals, spread

Exact Paragraph and Line Location

Reading Passage 3, Paragraph F, lines 315–318

Explanation

The passage says guard dogs can spread diseases to wild animals, including endangered Ethiopian wolves.

So, the answer is: diseases

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Question 39

Guard dogs may reduce the amount of ______ available to certain wild animals.

Keywords

reduce amount, wild animals, compete

Exact Paragraph and Line Location

Reading Passage 3, Paragraph F, lines 315–318

Explanation

Guard dogs may compete with other carnivores for food.

This can reduce the amount available to wild species.

So, the answer is: food

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Question 40

Guard dogs may protect ground-nesting birds from predators such as ______.

Keywords

birds, nests, predators

Exact Paragraph and Line Location

Reading Passage 3, Paragraph G, lines 319–323

Explanation

The passage says guard dogs can protect birds nesting in fields from predators that would normally raid their nests.

The predator specifically mentioned is foxes.

So, the answer is: foxes

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Cambridge 20 Test 4 Reading Answer Key

Reading Passage 1

1. teacher
2. charcoal
3. skyscrapers
4. flowers
5. bones
6. landscape
7. rivers
8. FALSE
9. TRUE
10. FALSE
11. TRUE
12. NOT GIVEN
13. NOT GIVEN

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Reading Passage 2

14. C
15. A
16. D
17. F
18. pumps
19. dams
20. float
21. crops
22. trees
23. B — Susanna Tol
24. E — Greg Spotts
25. A — Yanira Pineda
26. C — Elizabeth English

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Reading Passage 3

27. D
28. G
29. B
30. C
31. B
32. D — Julie Young
33. E — Bethany Smith
34. B — Silvia Ribeiro
35. C — Linda van Bommel
36. A — Dan Macon
37. jackals
38. diseases
39. food
40. foxes

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Bonus IELTS Reading Tips

Follow the Word Limit

Always check whether the instructions say:

• ONE WORD ONLY
• ONE WORD AND/OR A NUMBER
• NO MORE THAN TWO WORDS
• Choose a letter

For example:

• Correct: charcoal
• Incorrect: abstract charcoal

Extra words can make a correct answer wrong.

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Look for Paraphrases

IELTS questions often use different wording from the passage.

Question wording	Passage wording
worked as	became
paintings of the city	architectural pictures
close-up paintings	magnified images
initially inspired	at first sparked her imagination
over forty years	more than four decades
changing fashions	shifting art trends
chosen her career	determined to make her way as an artist
natural coastal protection	defend coastal areas
cost-effective	much cheaper
areas needing intervention	streets with low tree canopy cover
houses can float	rose with floodwaters
suitable for salt	salt-tolerant
involve residents	engage and benefit communities
future decades	20, 30, 40 years
keep predators away	chase away / mere presence
not widespread	not working with everybody
properly handled	managed and used properly
affect other species	spread diseases
reduce available resources	compete for food

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Understand FALSE and NOT GIVEN

FALSE

Choose FALSE when the passage provides information that directly contradicts the statement.

Example:

The statement says O’Keeffe was influenced by changing artistic fashions.

The passage says she remained independent from those trends.

Therefore: FALSE

NOT GIVEN

Choose NOT GIVEN when the passage does not provide enough information.

Example:

The patio paintings were described as inspirational.

The passage never says they were O’Keeffe’s favourites.

Therefore: NOT GIVEN

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Be Careful with Comparative Claims

Question 13 is a good example.

The statement says O’Keeffe produced more work than at any other time.

The passage discusses different periods of her career but never makes this comparison.

Therefore, the answer is NOT GIVEN.

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Match Information, Not Just Keywords

For Question 16, the word cheap is the key clue.

The passage says amphibious houses cost about one-third of replacing conventional foundations.

That makes Paragraph D the correct match for a cost-effective solution.

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Use Names as Location Markers

Matching-person questions become easier when you scan for names.

Examples:

• Yanira Pineda
• Susanna Tol
• Elizabeth English
• Greg Spotts
• Dan Macon
• Silvia Ribeiro
• Linda van Bommel
• Julie Young
• Bethany Smith

Once you find the name, read the surrounding two or three sentences carefully.

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Check Who Actually Expresses the Opinion

Do not match a statement simply because someone is mentioned nearby.

For Question 32, several people discuss predators.

But Julie Young is the person who directly explains that preventing livestock deaths can also prevent farmers from killing wolves.

Therefore: D

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Follow Passage Order in Completion Questions

Questions 1–7, 18–22 and 37–40 mostly follow passage order.

After locating one answer, continue reading from that point.

This saves time and reduces unnecessary scanning.

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Watch for Cause and Effect

IELTS often turns cause-and-effect relationships into questions.

Example:

Guard dogs → fewer livestock deaths → farmers less likely to kill predators

Understanding the relationship helps answer Questions 27 and 32.

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Read Around the Answer

Do not stop at the first matching word.

Read at least one sentence before and after it because the passage may contain:

• a contrast;
• a limitation;
• an exception;
• the actual answer after a distractor.

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Review Every Wrong Answer

After completing the reading test, identify why each mistake occurred.

Common reasons include:

• missing a paraphrase;
• confusing FALSE with NOT GIVEN;
• ignoring comparison words;
• exceeding the word limit;
• matching the wrong person;
• stopping after seeing one keyword;
• overlooking cause-and-effect relationships.